Collet chuck



Feb.27,194o. A. H. BREWB'ARTH mL 2,192,024

COLLET CHUCK Filed oct. 4, 1958 magi,

WITNESS ES Patented Feb. 27, 1940 Augst H. Br

PATENT Aori-ICE COLLET CHUCK eitbarth and Harry Anderson,

Valparaiso,

Application .october 4, 193s, serial No. 233,230

` zclaims.; (c1. 21e- 51) This invention relates to chucks, and more par-v ticularly to collet chucks which are used on lathes, milling, grinding and similar types of machines, to hold the material to be worked.

Various types of chucks have been used in the past, and an object of this invention is to provide a chuck simple in operation, economical in construction, and one which Wi rial to be worked in a rm grip.

ll `hold the mate- A further object of the invention is to provide a collet chuck in which the changing of the collet is simplified and speeded up. In the accompanying drawing- Fig. 1 is a cross sectional view of a device embodying our invention, taken on the line I-'I of Fig. 2;

Fig. 2 is a plan view partly in cross section; Fig. 3 is a view of a collet suitable for use in our chuck;

Fig. 4 is a cross sectional view 4-4 of Fig. 1;

taken on the line Fig. 5 is a rear view of the collet shown in Fig. 3;

Fig. 6 is a cross sectional view of the collet taken on the line 6 6 of Fig. 3.

Referring more particularly to thev drawing, we provide a housing II) which is threaded at its rear end II for adaption to the machine upon which it is to be used. The housing its front end to form a cavity I0 is undercut at I2 adapted to receive and position a forward housing I3.A A screw I4 extends through the housing ing I3 to hold the two together.

I0 into the hous- Between the two housings is an annular channel I5 adapted to receive a cammed hand wheel I6. The hand wheel I6 has on its inner surfaces -cammed sections I'I, two or more in number. The housing I3 contains a plurality of slots I8 running at right angles and coinciding with the cammed surfaces I1. Pivoted means ofthe pins I9 are dogs are substantially triangular in being at one angle thereof and in these slots by 20. The dogs 20 shape, the pivot having extended through the inner surface of the housing I3 fingers 2| constituting another point of the triangle. The third point of the triangle consists ln the arm 22 faces `I`I of the hand wheel I6.

adapted to engage the cammed sur- A spring 23 seated in thevhousing I3 engages the end of the dog 20 to hold it against the cammed surface, and an additional spring 24 is seated in the housing I3 and contacts the dog 20 at one end and a pin 25 extending into the center of the housing I3 at its other end.

A collet 30 is provided', havin g a collar 3l and an annular depressed portion 32. The collet forwardly of the collar 3| is cut through one or more places 33 in order to provide for expansion and contraction. The collar 3l is provided with a plurality of grooves 34 to allow the collet to be 5 36, the circumference of which increases to the 10 outer end to give an angle surface 31. The bearing surface 35 is provided with a plurality of grooves 38.

The inner portion of the housing I3 has an angular surface 39 which, when the collet is inserted 15 in the housing, contacts the surface 31.

In operation the hand wheel is turned so the cammed surface I1 will exert the least possible pressure on the 'arm 22 and the collet is inserted in the housing I3 so that the pins 25 pass through 20 the grooves 34. The collet is then turned; until the pins 25 slip into the grooves 38 where they hold the collet against accidental turning. By turning the hand wheel I6 toward the operator or in a counter-clockwise direction, the cammed 25 surface yI'I will exert pressure on the arm 22 causling the dog 20 to pivot on the .pin I9 and to exert The tapered surface 39 will then exert pressure 3()` against the surface 3l of the jaws 36 causing them to close and grip the material placed between the jaws by the contraction of said jaws.

It will thus be seen that in inserting or changing a collet, the operator needs only to move the 35 hand wheel I6 a very short distance to release it and to tighten the pressure against the dogs 20 which in turn cause the contraction of or allows the expansion of the jaws 36 of the collet 30. In changing the collet by turning the hand 4() wheel I6 a short distance in a clockwise direction, pressure on the arm 22 of the dog- 20 is released land the springs 23 and 24 relieve the pressure from the collar 3l. This likewise releases the pressure on the spring 24 so that the 45 pin 25 may be sprung out of the groove 38, the collet turning until the pin 25 coincides with the groove 34, and removed from the chuck.

y1t will be lseen that by the use of this device a strong pressure may be exerted against the 50 jaws of the collet by a, simple operation of the hand wheel, and the collet 3|] will more firmly hold the material to be worked.

While the hand wheel I6 may be constructed of a single piece, we have found that an additional advantage exists in making it of two.

pieces. It will be seen from the drawing that the wheel is constructed of an outer section 40 and an inner section 4| held together by a screw 52. The section 4l directly contacts the arm 22 and may contain the cammed surfaces. It may be made of harder material than the balance 40 of the wheel I6 and by such construction it would not .be necessary to. cam the portion 40. i Y

It will also be appreciated'that, while in the drawing we have shown one type of collet, many and varied types of collets and other tools maybe used with this chuck by providing them'with the collar 3l, and the conventional collet may be used by the addition of ai loose threaded collar which may either be placed back of the dogs 2| and held in place by dowel pinsor which may be provided with the groove 34 and placed on the end of the collet before insertion into the chuck.

We claim:

1. A device of the character described, including a chuck, dogs in said chuck with arms extending through said chuck, a wheel having an internally cammed surface mounted on said chuck and cooperating with one end of said dogs, whereby the turning of therwheel Will cause said cammed surface to exert `pressure on said dogs and to move said arm rearwardly,

spring members cooperating with said dogs and with a pin extending into 4the interior of said chuck, a collet having a collar at its rearward end adapted to be engaged by said arms, and grooves in said collar and additional grooves on the outer surface of said collet, said grooves in the collar being adapted to allo'wvthe collet to be passed by said arms and said grooves on thesurface of the collet and being adapted to engage said pins after the insertion of the collet into the chuck to prevent accidental turning v, i thereof.

` 2. In a device of the character described, in-

cluding a chuck, dogs in said chuck with arms extending through said chuck, a wheel having cam surfaces mounted on said chuck yand co` operating with one end of said dogs, whereby i E.the turning of the wheel will cause said cam surfaces to exert pressure on said dogs and to Inove 'said arms rearwardly, spring members cooperating wth said dogs and with a pinA extending into the interior of'said chuck, a collet hav-` lng a collar on its rearward end adapted to be engaged by said arms, and grooves in the outer surface of said collet adapted to engage said Vpins after the insertion of the collet into the chuck to prevent the accidental turning theres of. i

AUGUST H. BREITBARTH. HARRY ANDERSON. v 

